CONCORD -- Republican U.S. Sen. Kelly Ayotte, under fire from some conservatives for her support for the "Gang of Eight" immigration reform bill, was defended as courageous by four former chairmen of the New Hampshire Republican Party Thursday.

Ayotte, who announced her support for the bill last weekend, Thursday voted in support of the first of many proposed amendments that would toughen the bill's security provisions.

At a news conference, former chair Steve Duprey, now one of the state party's representatives on the Republican National Committee, said that to call the bipartisan bill an amnesty measure is "poppycock" and a "false slogan."

Duprey, a friend of and former top advisor to "Gang of Eight" member, former presidential hopeful and Ayotte Senate mentor John McCain, said the bill "is a 10- to 11-year road to legal status that includes not receiving welfare benefits, having a job, not engaging in any criminal activity, learning English.

"I applaud Senator Ayotte for her courage," said Duprey, who said she showed "refreshing independence."

"Kelly Ayotte is doing the right thing," said Fergus Cullen, who earlier this year created the 501 (c)(4) nonprofit advocacy group Americans by Choice to promote immigration reform from what he calls a "center-right" perspective.

"We can have honest debates within our party, on the conservative side, about some of the details of the bill," said Cullen, predicting passage of several amendments "that will improve a good bill and make it better.

"But the vast majority of Republicans can and should be supporting the general thrust of the bill," he said.

The bill would allow most of the nation's 11 million illegal immigrants to apply for U.S. citizenship within 13 years. It would add $6.5 billion in border security funding, require all U.S. business owners to check the immigration status of hires through an "e-verify" system and change the legal immigration system to bring in more high-tech and lower-skilled workers on short-term HB-1 visas.

To qualify for citizenship, immigrants would be placed in temporary legal status for at least 10 years, pass a criminal background check, learn English, pay taxes, fees and at least $2,000 in fines.

Critics say the bill in its current form is not strong enough on border security and believe the borders should be secured before the remainder of the new system takes effect.

Proponents of the current bill call that unrealistic.

Earlier Thursday, a border security amendment to the bill, authored by Sen. Chuck Grassley, R-Iowa, failed on a 57 to 43 vote.

As for additional border security amendments still to be considered, Ayotte "is studying all of them," said her spokesman, Jeff Grappone.

He pointed out that in a recent opinion piece, Ayotte wrote, "Consistent with my priorities, the legislation includes more border agents, more fencing, and better surveillance technology. And during the upcoming debate, I will support strengthening the legislation's border security measures even further."

Shaheen said in a statement she voted to kill the Grassley amendment "because it would have undermined bipartisan efforts to fix a broken immigration system. The bill significantly beefs up border security but the Grassley amendment would've weakened those efforts by delaying the collection of fines and fees that fund the law's border security provisions. It's time to move forward with common sense immigration reform without further delay."

She noted the Republican co-sponsors of the original bill also opposed the amendment.

Cullen said the bill "modernizes, reforms and improves a broken immigration system in a way that will create jobs and improve our economy."

He pointed out that the H1-B visa quota of 65,000-a-year, was filled this year in five days.

"That is holding back our economy," said Cullen, who said the bill broadens that program.

"If you are concerned about border security, as we know that many of our fellow conservatives and Republicans are, the single most effective thing that can be done is to advance a guest worker program," said Cullen.

"Give people a choice between a legal path and an illegal path and people will choose the legal one," he said.

Duprey, a business owner and employer, said he is a "fan" of the e-verify system, calling it "remarkably simple. It costs nothing, it takes less than two minutes and it works.

"Republicans cannot be hypocrites and say they do not support an e-verify system because it's burdensome on business," said Duprey. "That's just untrue."

Duprey said his support for the bill is not based on political considerations.

"This is not about whether it improves our chances electorally, although, frankly, I think it will," said Duprey. "But that is irrelevant."

Former state GOP chairman Wayne MacDonald, said "a number of Republicans were upset" when he and four other former GOP chairs wrote an opinion piece last week in the New Hampshire Union Leader supporting the bill.

"It was a decision that we all considered very carefully," he said.

MacDonald said the state GOP took "beatings" at the polls in Manchester and Nashua during the 2012 election, "in part because of the immigration issue.

"Until we can more effectively make our case to all of the voters, we will continue to face an uphill climb," he said.

For the past few months, Ayotte has been criticized by liberals and moderates for opposing a key gun control measure. Now, many conservatives are upset with her for her support for the immigration bill.

National Review Online, for instance, opined, "Thoughtful is one thing her support for that bill is not. In an op-ed published on her website, Ayotte shows no sign of knowing what the main objections of the bill's critics are, much less of having grappled with them."

But Duprey said neither her gun vote nor her support for the immigration bill will have any "long-term effect" on the views rank-and-file voters have of Ayotte.

"I think the people of New Hampshire, regardless of party, respect senators who they think work hard, study hard, listen to all the debate and make the decisions they think are in the best interests of New Hampshire and the country, and let the chips fall where they may," he said.

"In the last analysis," Ayotte's vote against the gun control measure and for immigration reform will be political "assets" for her.

"The great thing about Kelly Ayotte is her refreshing independence," said Duprey.

The state Republican Party's platform takes a hard-line on immigration, with its "Federalism" plank saying, "Strengthen national border security; enforce immigration laws; oppose any form of amnesty for illegal aliens; define trespass to include illegal presence in New Hampshire."

Current state GOP chair Jennifer Horn, who was not at the press conference, said afterward, "While we understand there are differing views on this issue in both parties, it is clear that Senator Ayotte has taken a bold stand on this legislation. Senator Ayotte continues to demonstrate that she is a forceful and independent leader who is willing to be up-front and honest about her positions."

Former party chair Jayne Millerick, who also is a long-time Ayotte and McCain supporter, also attended news conference, as did two GOP businessmen supportive of the bill.

David Cuzzi, president of Manchester-based Prospect Hill Strategies and a former top legislative aide for national security and other key issues to former Sen. John E. Sununu, said that since he was on Capitol Hill, "The politics are the same but the problem has only gotten worse.

"People can't let perfect be the enemy of good," said Cuzzi. He said Ayotte's job "is to find common ground," calling her a conservative, "but also a reformer."